Custom GPTs Are Retiring on December 11, 2026: How to Migrate Your GPT to a ChatGPT Plugin

If you built a custom GPT for your blog, business or clients, there is a deadline you cannot ignore. OpenAI has announced that custom GPTs will be retired on December 11, 2026, and creators are being asked to move them to the newer ChatGPT plugin format. Enterprise workspaces with an approved deferral get extra time, until February 11, 2027. This guide explains in plain language what is changing, what you will lose if you do nothing, and exactly how to migrate your GPT step by step.

What Is Changing and When?

Since late 2023, custom GPTs have let anyone package instructions, files and tools into a reusable assistant. OpenAI is now consolidating this into plugins, which combine skills, connected apps and instructions in one format that also works across other OpenAI surfaces. According to OpenAI’s help center, existing GPTs will stop working after the retirement date unless they are migrated.

Date	What happens
September 2026	Retirement and migration tools announced
December 11, 2026	Custom GPTs retired for most users
February 11, 2027	Final date for Enterprise workspaces with an approved deferral

What Transfers to a Plugin — and What Doesn’t

The migration tool moves the core of your GPT, but not everything comes across automatically.

What carries over

Your instructions (they become the plugin’s skill instructions)
Knowledge files you uploaded
Connected apps that are supported in the plugin system

What does not carry over

Custom actions (API calls you configured with an OpenAPI schema) need to be rebuilt
The model selection you set on the GPT
Sharing settings — you will need to share the plugin again

If your GPT relied heavily on custom actions, start the migration early. Rebuilding API connections and testing them takes the most time.

Step-by-Step: How to Migrate Your Custom GPT

Back up everything. Copy your GPT’s instructions into a document and download your knowledge files. Screenshot your action settings and conversation starters.
Open My GPTs. In ChatGPT, go to your profile, then “My GPTs”.
Choose “Migrate to plugin”. Select the GPT and start the migration. ChatGPT creates a draft plugin using your instructions and files.
Review the instructions. Plugins can use shorter, task-focused skills. Clean up outdated lines and add clear output formats.
Rebuild actions. Re-add any API connections using the plugin’s supported app or connector options.
Test with real prompts. Run the same 10–15 prompts your users usually send and compare results with the old GPT.
Share again. Update your links on your website, newsletter and social profiles.

How to Write Better Plugin Instructions

Migration is a great chance to improve quality. Use this simple structure for your instructions:

Role: “You are an SEO assistant for small business blogs.”
Inputs: “The user will paste a blog draft or a topic.”
Steps: “1) Identify the main keyword. 2) Suggest a title under 60 characters. 3) Write a meta description under 155 characters.”
Output format: “Return a table with Title, Meta, Keyword and three H2 ideas.”
Limits: “Do not invent statistics. Ask for missing details.”

10 Prompts to Test Your Migrated Plugin

“Summarise what you can do in five bullet points.”
“Here is a sample input: [paste]. Produce the standard output.”
“What information do you need from me before you start?”
“Rewrite your last answer for a beginner.”
“Use my uploaded file to answer: [question].”
“Show the result as a table.”
“What are your limitations?”
“Give me three alternative versions.”
“Check your answer for factual claims I should verify.”
“Create a checklist from this result.”

What If You Only Use Other People’s GPTs?

If you rely on popular GPTs made by others, check whether the creator has published a plugin version. Many creators will announce new links. If a GPT you use is not migrated, you can usually recreate its behaviour with a saved prompt or a Project in ChatGPT.

Common Migration Problems and How to Fix Them

Problem	Likely cause	Fix
Plugin answers differently from the old GPT	Model selection did not carry over	Add clearer step-by-step instructions and an example output
API calls fail	Custom actions are not migrated	Rebuild the connection using supported apps or connectors
Users cannot find your plugin	Old GPT link no longer works	Share the new plugin link on your site and social profiles
Answers ignore your files	Files not referenced in instructions	Tell the plugin when and how to use each file

Pre-Deadline Migration Checklist

List every GPT you own and mark which ones are still used.
Retire GPTs nobody uses instead of migrating them.
Export instructions, conversation starters and knowledge files.
Note every custom action and the API it calls.
Migrate the most-used GPT first and test it for a week.
Update links in blog posts, YouTube descriptions and email signatures.
Tell your users about the new link before December 11.

Example: Migrating a Blog SEO GPT

Imagine a GPT called “Blog Title Helper” with instructions, a PDF style guide and no actions. Migration takes about ten minutes: run the migration tool, keep the instructions, confirm the PDF is attached, test five topics, and share the new link. A GPT that pulled keyword data from an external SEO API would take longer, because that action must be rebuilt and tested with your API key in the new setup.

Frequently Asked Questions

Will my GPT stop working on December 11, 2026?

Yes, for most users. Migrate before then to keep it available.

Is migration free?

The migration tool is part of ChatGPT. Plan requirements for creating plugins may vary, so check your account.

Do I lose my GPT’s conversations?

Past chats remain in your history, but the GPT itself is retired.

Can I migrate a GPT with custom actions?

Yes, but actions do not transfer automatically and must be rebuilt.

Final Thoughts

The retirement of custom GPTs is a big change, but the migration path is clear. Back up your work, use the built-in migration tool, rebuild your actions, and test carefully. Doing it in October or November gives you plenty of time to fix issues before the December 11 deadline.

Note: AI products change quickly. The features, plans and dates in this article were checked in early October 2026. Always confirm the latest details on the official product page before you buy or rely on a feature.